1. Technical Field
The present disclosure relates to a display device.
2. Description of the Related Art
In recent years, demand has been increased for display devices, for example, for mobile apparatuses such as a cellular telephone and electronic paper. In such display devices, each one pixel includes a plurality of sub-pixels that output different colors. Various colors are displayed using the single pixel by switching on and off display at the sub-pixels. Display characteristics such as resolution and luminance have been improved year after year in such display devices. However, an aperture ratio is reduced as the resolution increases, so that luminance of a backlight needs to be increased to achieve high luminance. An increase of the luminance of a backlight increases power consumption of backlight. To solve this problem, a technique has been developed for adding a white pixel serving as a fourth sub-pixel to red, green, and blue sub-pixels known in the art (for example, refer to Japanese Patent Application Laid-open Publication No. 2010-33014 (JP-A-2010-33014)). According to this technique, the white pixel enhances the luminance, contributing to lowering the current value of the backlight apparatus and reducing the power consumption.
Examples of a known driving method for an image display panel include, but are not limited to, a column inversion driving method, a line inversion driving method, a dot inversion driving method, and a frame inversion driving method. The column inversion driving method is a driving method for applying voltages so that one line (column) and another line adjacent thereto among lines each composed of sub-pixels or pixels including combined sub-pixels, can be different in potential relative to a reference potential, and inverting the polarities of the voltages to be applied at predetermined cycles. Accordingly, it is known that charge and discharge amounts are small in a signal line and low power consumption is achieved in the column inversion driving method as compared with the dot inversion driving method (for example, refer to Japanese Examined Patent Application Publication No. H5-43118).
An image display panel to which the fourth sub-pixel is added involves increase of an area per pixel, so that such an image display panel with higher definition has been demanded. Accordingly, liquid crystal display panels have been studied that have an arrangement configuration in which: first columns each including first sub-pixels, second columns each including second sub-pixels, and third columns each including third sub-pixels and the fourth sub-pixels are sequentially arranged; in each of the third columns, the third sub-pixels and the fourth sub-pixels are alternately arranged in a column direction; and, across the third columns, in the same row, the third sub-pixels and the fourth sub-pixels are alternately arranged so that each adjacent two of the third columns in a direction along a row direction may contain the third sub-pixel and the fourth sub-pixel. In such a configuration, however, although a pixel area can be prevented from being increased and high definition can be achieved even when the fourth sub-pixel is added, deterioration in display quality called crosstalk may be caused when the technique disclosed in Japanese Examined Patent Application Publication No. H5-43118 is applied to further suppress the power consumption.
For the foregoing reasons, there is a need for a display device that suppresses power consumption and reduces deterioration in display quality.